Ender's Game author Orson Scott Card has come under fire for his views on gay marriage.

The website Geek Out has called for people to boycott watching the film and buying its merchandise in protest.

The website writes: "'Skip Ender's Game' is a call to action. Do NOT see this movie! Do not buy a ticket at the theatre, do not purchase the DVD, do not watch it on-demand. Ignore all merchandise and toys.

"However much you may have admired his books, keep your money out of Orson Scott Card's pockets."

Card wrote the book in 1985 about talented children who are trained how to fight an insectoid species called 'Buggers'.

The website quoted Card from an article in 1990 where he said: "Laws against homosexuality should remain on the books."

Card has released a statement following the campaign reports The Guardian.

The author said: "Ender's Game is set more than a century in the future and has nothing to do with political issues that did not exist when the book was written in 1984,

"With the recent Supreme Court ruling, the gay marriage issue becomes moot. The full faith and credit clause of the constitution will, sooner or later, give legal force in every state to any marriage contract recognized by any other state."

Card added: "Now it will be interesting to see whether the victorious proponents of gay marriage will show tolerance toward those who disagreed with them when the issue was still in dispute."

Harrison Ford on the Jimmy Kimmel show

The Boy in the Striped Pyjamas star Asa Butterfield will play Ender, with Abigail Breslin and Harrison Ford also starring.

The film will preview at Comic-Con in San Diego on Thursday, July 18. Members of the cast will appear as part of a panel, but Card is not likely to attend.

Ender's Game will be released on October 25 in the UK, October 31 in Australia and November 1 in the US.